Mic.com

If you’re a left-leaning, liberal or even vaguely non-Nazi male-identifying person with opinions online, you’ve probably been called all sorts of too-nerdy-to-actually-be-offensive names: “cuck,” “beta,” “white knight,” “pajama boy.” The alt-right — that loosely organized collective of white nationalists and trolls — certainly has a knack for branding.
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So, the whole “soy milk gives men breasts” thing is bullshit, right?
Totally. That’s pretty well-established. The case referenced in Allsup’s video was an isolated incident about a man who drank nearly a gallon of soy milk a day.

About

“Soy Boy” is the new 2017 meme insult used in right-wing online communities to describe the common leftist-leaning weak man. It has similarites the the term “cuck”. The term is based on the fact that soybeans emasculate you.

A ordinary soy boy cuckold

Origin

As most other memes it originated on an imageboard in this case probably 4chan.org. This oldest, archived post is a combination of the well used term cuckold and the new inveted soyboy.

First Soy Boy post on 4chan

Spread

Slang used to describe males who completely and utterly lack all necessary masculine qualities. This pathetic state is usually achieved by an over-indulgence of emasculating products and/or ideologies.

The origin of the term derives from the negative effects soy consumption has been proven to have on the male physique and libido.

The average soy boy is a feminist, nonathletic, has never been in a fight, willprobably marry the first girl that has sex with him, and likely reduces all his arguments to labeling the opposition as “Nazis”.